Draw the lowest energy conformation adopted by each of the following molecules :
(a) trans-1,2-dimethylcyclohexane (b) cis-1-tert-butyl-2-chlorocyclohexane
(c) trans-1-bromo-2-methylcyclohexane (d) cis-4-tert-butylcyclohexanol

Question

Draw the lowest energy conformation adopted by each of the following molecules :

(a) trans-1,2-dimethylcyclohexane (b) cis-1-tert-butyl-2-chlorocyclohexane

(c) trans-1-bromo-2-methylcyclohexane (d) cis-4-tert-butylcyclohexanol

TestHub · Accepted Answer

(a) trans-1,2 can be diequatorial - both methyl groups equatorial :

structure

(b) cis-1,2 is always axial-equatorial; the much larger tert-butyl group takes the equatorial position and $Cl$ goes axial :

structure

(c) trans-1,2 can again be diequatorial - both substituents equatorial :

structure

(d) cis-1,4 is always axial-equatorial; the large tert-butyl group insists on the equatorial position, forcing $OH$ axial :

structure

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